Ventilation system

ABSTRACT

A ventilation system is disclosed. The ventilation system of the present invention includes a heat-exchanger having at least two unit heat-exchange elements arranged in parallel for heat exchange between supplied outside air and exhausted room air, an air-supply duct having one side for making an outdoors be in communication with an inside of the heat-exchanger and the other side for making an indoor space be in communication with the inside of the heat-exchanger to supply outside air into the indoor space, and an air-exhaust duct having one side for making the indoor space be in communication with the inside of the heat-exchanger and the other side for making the outdoors be in communication with the inside of the heat-exchanger to exhaust room air outdoors, wherein an air-supply channel is formed for making one side of the air-supply duct be in communication with the other side of the air-supply duct and an air-exhaust channel is formed in a diagonal direction of the air-supply channel for making one side of the air-exhaust duct be in communication with the other side of the air-exhaust duct within the heat-exchanger.

This application claims the benefit of the Patent Korean Application No.P2005-74693, filed on Aug. 16, 2005, which are hereby incorporated byreference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a ventilation system, moreparticularly, to a ventilation system which improves heat-exchangingefficiency in a heat-exchanger.

2. Discussion of the Related Art

In general, ventilation means to make room air pleasant. Morespecifically, ventilation means to discharge and remove polluted roomair outside to supply fresh outside air to a room, thereby makingpleasant indoor circumstances maintained.

Air within an airtight space may contain more carbon dioxide due tohuman perspiration as time goes by. Hence, the high carbon dioxidecontent in a room may affect the human perspiration. Thus, in case thatmany people have to stay together in a small room such as an office or avehicle, it is necessary to replace the polluted room air with freshoutside air regularly. A ventilation system is commonly used at thattime.

According to a well-known conventional ventilation system in the relatedart, only room air is forcibly ventilated outside by using oneventilator. However, in case that only room air is forcibly ventilatedoutside by using one ventilator, cooled or heated room air is dischargedoutside without any filtering. Also, outside air is drawn through a dooror a window shield without heat-exchanging, thereby resulting in causingunnecessary cost in cooling/heating a room.

Also, if cooled/heated air is suddenly drawn into a room from anoutside, people in the room might feel unpleasant due to the drasticallychanged temperature. Especially, in case only room air is dischargedoutside in a state where a window shield or a door is closed, freshoutside air is shut off to cause an anoxia symptom. Hence, sincehumidity control for a room is not performed at all, pleasant internalcircumstances in spite of a ventilation system provided therein.

To solve the above problem, a ventilation system has been suggested, inwhich outside air is heat-exchanged with room air discharged outside andthen supplied into a room. Referring to FIG. 1, the above conventionalventilation system will be described.

Generally, the heat-exchanging type ventilation system includes aheat-exchanger 1 having a box shape, an air-supply channel incommunication with an outside and an air-exhaust channel incommunication with an inside of a room.

The heat-exchanger 1 is generally box-shaped and has an air-supply fan15, an air-exhaust fan 25 and a heat-exchange element 5 providedtherein.

The air-supply channel and the air-exhaust channel pass through theheat-exchanger 1. The air-supply channel passes an air-supply inlet 11,the inside of the heat-exchanger 1 and an air-supply outlet 13. Theair-exhaust channel passes through an air-exhaust inlet 21, the insideof the heat-exchanger 1 and an air-exhaust outlet 23.

Thus, in the air-exhaust channel which discharges polluted room airoutside, air flows to an internal air-exhaustion duct, theheat-exchanger and an external air-exhaustion duct in order. A first endof the internal air-exhaustion duct is in communication with a room anda second end thereof is connected to the air-exhaustion inlet 21 of theheat-exchanger 1. A first end of the external air-exhaustion duct isconnected to the air-exhaust outlet 23 of the heat-exchanger 1 and asecond end thereof is in communication with an outside.

Also, in the air-supply channel which supplies fresh outside air into aroom, air flows to an external air-supply duct, the heat-exchanger andan internal air-supply duct in order. A first end of the externalair-supply duct is in communication with an outside and a second thereofis connected to the air-supply inlet 11 of the heat-exchanger 1. A firstend of the internal air-supply duct is connected to the air-supplyoutlet 13 of the heat-exchanger 1 and a second end thereof is incommunication with a room.

As considering a cause of air flow, the air-supply fan 15 is operated togenerate absorption force for absorbing outside air (OA). Hence, outsideair (OA) is supplied into a room through the air-supply channel. Here, areference of (SA) which is not described is ‘supply air’. Also, theair-exhaust fan 25 is operated to generate absorption force forabsorbing room air (RA). Hence, room air (RA) is exhausted outsidethrough the air-exhaust channel. Here, a reference of (EA) which is notdescribed is ‘exhaust air’.

A way of heat-exchanging between room air (RA) and outside air (OA)drawn into the heat-exchanger 1 will be described.

First of all, room air (RA) is drawn to a first lower portion of theheat-exchange element 5 from the inside of the heat-exchanger 1 anddischarged to a first upper portion of the heat-exchange element 5, andthen the room air (RA) is out of the heat-exchanger 1. Together withthat, outside air (OA) is drawn to a second lower portion of theheat-exchange element 5 from the inside of the heat-exchanger 1 anddischarged to a second upper portion of the heat-exchange element 5, andthen the outside air (OA) is out of the heat-exchanger 1.

That is, the path of the room air (RA) and the path of the outside air(OA) are crossed each other within the heat-exchange element 5. Heatbetween the room air (RA) and the outside air (OA) is exchanged througha side wall of each path.

Here, a heat-exchange element in which heat is exchanged by onlytemperature difference between the room air (RA) and the outside air(OA) is called as ‘sensible-heat-exchange element’. Whereas, aheat-exchange element in which heat is exchanged by humidity differencebetween RA and OA rather than the temperature difference is called as‘total-heat-exchange element’.

Recently, the total-heat-exchange element is used a lot more to enhanceheat-exchanging efficiency.

However, in the conventional ventilation system according to the relatedart described above, the size of the heat-exchange element 5 should belarge to enhance heat-exchanging efficiency, thereby causing a problemthat the height of the heat-exchanger 1 should be high.

By the way, according to the conventional ventilation system operated byrelatively high wind force, flux of air draw in into the heat-exchangeelement 5 is getting fast. Thereby, the faster the air flux is getting,the lower heat-exchanging efficiency should be getting.

Thus, the volume of the heat-exchange element 5 should be large.Although the heat-exchanger 1, generally, is installed on a ceiling of aroom, the height of the heat-exchanger 1 is getting high to enlarge thevolume of the heat-exchange element 5. Thereby, to compensate that,there may be a problem that the height between each floor of a buildingshould be higher.

Therefore, it is preferred that the height of the heat-exchanger 1 isnot more than a predetermined height and there have been demands for aheat-exchanger 1 which can enhance heat-exchanging efficiency withoutenlarging the height of the heat-exchanger 1.

Furthermore, the conventional heat-exchanger 1 has a problem of highproduction cost, because the heat-exchange element 5 should be changedaccording to the size of the heat-exchanger 1.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a ventilation system.

An object of the present invention is to provide a ventilation systemwhich can maintain height of a heat-exchanger uniformly with highheat-exchange efficiency.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, aventilation system includes a heat-exchanger having at least two unitheat-exchange elements arranged in parallel for heat exchange betweensupplied outside air and exhausted room air; an air-supply duct havingone side for making an outdoors be in communication with an inside ofthe heat-exchanger and the other side for making an indoor space be incommunication with the inside of the heat-exchanger to supply outsideair into the indoor space; an air-exhaust duct having one side formaking the indoor space be in communication with the inside of theheat-exchanger and the other side for making the outdoors be incommunication with the inside of the heat-exchanger to exhaust room airoutdoors, wherein an air-supply channel is formed for making one side ofthe air-supply duct be in communication with the other side of theair-supply duct, and an air-exhaust channel is formed in a diagonaldirection of the air-supply channel for making one side of theair-exhaust duct be in communication with the other side of theair-exhaust duct within the heat-exchanger.

Here, the ventilation system of present invention may further includesan air-supply fan scroll having an air-supply fan for supplying outsideair into the indoor space in the air-supply channel and a motor foroperating the air-supply fan, and an air-exhaust fan scroll having anair-exhaust fan for exhausting room air outdoor in the air-exhaustchannel and a motor for operating the air-exhaust fan. The air-supplyfan scroll and the air-exhaust fan scroll may be provided in the sameportion of the heat-exchanger with respect to the heat-exchange element.

The air-supply channel and the air-exhaust channel may be in right/leftand upward/downward symmetry. The ventilation system further comprises aguide for partitioning off the air-supply channel and the air-exhaustchannel.

The heat-exchanger further includes a bypass channel for supplyingoutside air into the indoor space without outside air passing the unitheat-exchange element, and a bypass damper for selectively shutting offthe bypass channel.

The air-supply fan and the air-exhaust fan may be double suction fans,respectively. The unit heat-exchange element is a total-heat-exchangeelement. More specifically, the unit heat-exchange element may be ahexagonal parallel type heat-exchange element.

Preferably, the air passing through the unit heat-exchange element isdrawn from an air drawing surface of the unit heat-exchange element in adiagonal direction with respect to a center of the unit heat-exchangeelement and discharged from an air discharging surface of the unitheat-exchanging surface in a diagonal direction with respect to a centerof the unit heat-exchange element.

Here, the ventilation system according to the present invention mayfurther include a channel guide casing formed on an air drawing surfaceand an air discharging surface of the unit heat-exchange element todrawn/discharge air in a diagonal direction with respect to the centerof the unit heat-exchange element. The air-supply channel and theair-exhaust channel are partitioned by a guide within theheat-exchanger, the air-supply channel and the air-exhaust channel arein a right/left and upward/downward symmetry within the heat-exchanger.

The ventilation system of the present invention has followingadvantageous effects.

First, the ventilation system of the present invention has anadvantageous effect of less pressure loss, because an air path withinthe heat-exchanger, especially within the heat-exchange element, isimproved into a right/left and upward/downward air path.

Second, the ventilation system of the present invention has anotheradvantageous effect of high heat-exchange efficiency, because the volumeof the heat-exchange element is enlarged without increasing the heightof the heat-exchanger.

Third, the ventilation system of the present invention has still anotheradvantageous effect that capacity change of a ventilation system may beappropriately dealt with, because the heat-exchange element has aconfiguration in which the unit heat-exchange elements are connected inparallel.

Finally, the ventilation system of the present invention has stillanother advantageous effect of reduced pressure loss, because the airchannel drawn/discharged into/from the unit heat-exchange element isimproved more smoothly by the channel guide casing.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a perspective view illustrating key parts of a conventionalventilation system according to the related art;

FIG. 2 is a perspective view illustrating a ventilation system accordingto an embodiment of the present invention;

FIG. 3 is perspective view illustrating a path within a heat-exchangeelement of a ventilation system according to the embodiment of thepresent invention; and

FIG. 4 is a perspective view schematically illustrating a configurationof a heat-exchanger of a ventilation system according to anotherembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts and thedetailed description thereof will be omitted.

As shown in FIG. 2, a ventilation system according to an embodiment ofthe present invention includes a heat-exchanger 100, an air-supply duct(not shown), an air-exhaust duct (not shown), an air-supply channel 120and air-exhaust channel 130.

A heat-exchange element 140 is provided in the heat-exchanger 100 toallow supplied outside air (OA) and exhausted room air (RA)heat-exchanged. The heat-exchange element 140 has at least two unitheat-exchange elements 141 connected each other in parallel. In FIG. 2,six unit heat-exchange elements 141 are connected in parallel.

The unit heat-exchange element 141 may be a sensible-heat-exchangeelement which exchanges heat-exchanges by using temperature differencebetween the outside air (OA) and the room air (RA). Preferably, the unitheat-exchange element 141 is a total-heat-exchange element whichheat-exchanges by using humidity difference as well as temperaturedifference to enhance heat-exchanging efficiency.

An air-supply duct has one side for making an outdoors be incommunication with an inside of the heat-exchanger 100 and the otherside for making an indoor space be in communication with the inside ofthe heat-exchanger 100 to supply outside air (OA) into the indoor space.

Likewise, an air-exhaust duct has one side for making the indoor spacebe in communication with the inside of the heat-exchanger 100 and theother side for making the outdoors be in communication with the insideof the heat-exchanger 100 to exhaust room air (RA) into the room.

An air-supply channel 120 is formed for making one side of theair-supply duct be in communication with the other side of theair-supply duct and an air-exhaust channel 130 is formed for making oneside of the air-exhaust duct be in communication with the other side ofthe air-exhaust duct within the heat-exchanger.

The air-supply channel 120 and the air-exhaust channel 130 pass throughthe heat-exchanger 100 and cross each other in a diagonal directionwithin the heat-exchanger 100.

First of all, an air-exhaust channel (130, illustrated as dotted linearrows in the drawings) is formed within the heat-exchanger 100 so thatroom air (RA) is drawn into the heat-exchange element 140 through anair-exhaust inlet 131 and drawn from a first lower portion of theheat-exchanger 100 into the heat-exchange element 140 to be dischargedfrom a second upper portion of the heat-exchanger 100 to the outdoorsthrough an air-exhaust outlet 132.

Whereas, an air-supply channel (120, illustrated as solid line arrows inthe drawings) is formed so that outside air (OA) is drawn into theheat-exchanger 100 through an air-supply inlet 121 and drawn from afirst upper portion of the heat-exchanger 100 into the heat-exchangeelement 140 to be drawn from a second lower portion of theheat-exchanger 100 into the indoor space through an air-supply outlet122.

Thus, the air-supply channel 120 and air-exhaust channel 130 within theheat-exchanger 100 are diagonally formed. Thereby, the heat-exchanger100 of the present invention has less air inflow resistance than theheat-exchanger of the related art illustrated in FIG. 1.

Two chambers are formed in both opposite sides within the heat-exchanger100 with respect to the heat-exchange element 140 to divide a case 110of the heat-exchanger 100 into an upper/lower chamber, and the upper andlower chamber are partitioned by a guide 146. Thus, the air-supplychannel 120 and the air-exhaust channel 130 formed within theheat-exchanger 100 which has had one case 110 are in right/left andupward/downward symmetry.

Also, it is preferred that an air-supply fan scroll 125 and anair-exhaust fan scroll 135 are provided within the heat-exchanger 100.The air-supply fan scroll 125 includes an air-supply fan for supplyingoutside air (OA) into the indoor space in the air-supply channel 120 anda motor for operating the air-supply fan. The air-exhaust fan scroll 135includes an air-supply fan for exhausting room air (RA) outdoors in theair-exhaust channel 130 and a motor for operating the air-exhaust fan.That is for enabling a compact configuration of the heat-exchanger 100and for facilitating the installment of the entire ventilation systemwithout any difficulties.

Also, it is preferred that the air-supply fan scroll 125 and theair-exhaust fan scroll 135 are provided in the same portion of theheat-exchanger 100 with respect to the heat-exchange element 140 so thatthe air-exhaust channel 130 and the air-supply channel 120 may be formedin a diagonal direction and air may be drawn without being pushed touniformly distribute air inflow into each unit heat-exchange element 141connected in parallel.

As shown in FIG. 2, air is drawn into both opposite sides of each fanand discharged. It is necessary that a smooth air path should be formedto reduce pressure loss. Thus, preferably, the air-supply fan and theair-exhaust fan are double suction fans.

A reference number of 145 which is not described is a bypass channel andthe bypass channel will be described in another embodiment of thepresent invention later.

Next, the heat-exchange element 140 will be described in detail.

As shown in FIG. 2, the heat-exchange element 141 of the heat-exchanger100 according to the embodiment of the present invention includes atleast two unit heat-exchange elements 141 connected each other inparallel.

Although a hexagonal unit heat-exchange element 141 is illustrated inFIG. 2, it is also possible that a conventional tetragonal heat-exchangeelement, which makes an air path therein a cross flow type, may be usedas a unit heat-exchange element.

However, the hexagonal unit heat-exchange element 141 which makes an airpath a parallel flow type is preferred to enhance heat-exchangingefficiency.

Here, the parallel flow type is similar to a counter flow type of aconventional hexagonal heat-exchange element. An air path of theconventional counter flow type is in parallel each other and thedirection of air flow is opposite. However, the air path of the parallelflow type is in parallel each other and the direction of air flow isalso the same.

FIG. 3 schematically illustrates an air path within the unitheat-exchange element 141 and FIG. 3 illustrates the unit heat-exchangeelement 141 of FIG. 2 which is laid down on description's sake.

As shown in FIG. 3, an air path layer 148 where room air (RA) is drawnand exhausted outdoors and an air path layer 149 where outside air (OA)is drawn and exhausted into the indoor space are overlapped in the unitheat-exchange element 141. A heat-exchange film (not shown) is providedbetween the air path layers to allow heat between both layers exchanged.

Here, a rear right surface of the unit heat-exchange element 141 withrespect to the unit heat-exchange element 141 is an air drawing surfacewhere room air (RA) is drawn, and a front left surface thereof withrespect to the unit heat-exchange element 141 is an air dischargingsurface where heat-exchanged room air (RA) is exhausted. Also, a frontright surface of the unit heat-exchange element 141 with respect to theunit heat-exchange element 141 is an air drawing surface where outsideair (OA) is drawn, and a rear left surface thereof with respect to theunit heat-exchange element 141 is an air discharging surface whereoutside air (OA) is exhausted.

Heat-exchanging within the unit heat-exchange element 141 is performedin a cross flow type, after air is drawn into the unit heat-exchangeelement 141 and before air is discharged. Hence, an air path is formedin parallel in a center of the unit heat-exchange element 141 to performheat-exchanging in a parallel flow type.

Here, it is known that heat-exchange ratio is higher in a counter flowtype or a parallel flow type (the parallel flow type according to thepresent invention) than in the cross flow type.

The volume of the heat-exchange element 140 may be enlarged by parallelconnection of the unit heat-exchange element 141 as required in aventilation system with a high air force. Thereby, heat-exchangingefficiency may be enhanced by enlarging the number of the unitheat-exchange element 141. At that time, it is preferred that the unitheat-exchange element 141 is attachable/detachable in a verticaldirection of the heat-exchanger 100.

That is, if the unit heat-exchange element 141 is used, the number ofthe unit heat-exchange element 141 is adjusted without changing theentire heat-exchanger 100 or the heat-exchange element 140 even in casethat the capacity of the ventilation system is changed. Thereby,capacity variation may be appropriately dealt with.

Referring to FIG. 4, another embodiment of the present invention will bedescribed and the same description as the embodiment will be omitted.

FIG. 4 is a perspective view illustrating a heat-exchanger of aventilation system according to another embodiment of the presentinvention.

According to another embodiment, the same unit heat-exchange element asthe embodiment is provided. But, it is different that a predeterminedguide casing is further provided on an air inlet surface and an airoutlet surface of the unit heat-exchange element and the otherconfigurations are the same.

That is, an air-supply channel and an air-exhaust channel formed withina heat-exchanger 200 are the same as described in the above embodiment.Thus, in another embodiment, only the unit heat-exchange element 241will be described.

As shown in FIG. 4, a channel guide casing 242 and 243 is furtherprovided on an upper portion of the each unit heat-exchange element 241.

That is, drawn outside air (OA) is not perpendicularly drawn toward acenter of unit heat-exchange element 241, but diagonally drawn into anair drawn surface by the channel guide casing 242 and 243. In otherwords, a left portion of the channel guide 243 forms a channel forallowing air drawn therein in a predetermined direction of the air drawnsurface of the unit heat-exchange element 241.

Here, an air path drawn into the unit heat-exchange element 241 isformed narrowly by the left portion of the channel guide casing 242 and243. Thereby, the channel may be formed smoothly to reduce pressureloss.

Meanwhile, outside air (OA) drawn in a diagonal direction isheat-exchanged within the heat-exchange element 240 and dischargedoutside by the channel guide casing 242 and 243 formed in a lowerportion of the each unit heat-exchange element 241.

In that case, outside air (OA) is diagonally discharged from the airdischarging surface of the unit heat-exchange element 241.

Briefly, the channel guide casing 242 and 243 is provided on the airdrawing surface and the air discharging surface of the unitheat-exchange element 241 to form a channel drawing/discharging air in adiagonal direction with respect to the center of the unit heat-exchangeelement 241, not in a perpendicular direction.

Room air (RA) drawn through an air-exhaust inlet 221 is diagonally drawnin a lower left direction of the unit heat-exchange element 241 anddiagonally discharged in an upper right direction of the unitheat-exchange element 241.

As described above, since the channel of the unit heat-exchange element241 is formed in a right/left and upward/downward direction, the shapeof the channel drawn/discharged into/from each unit heat-exchangeelement 241 may be formed smoothly. Thus, the air-supply channel and theair-exhaust channel are formed in an S-shape from a view of the entireheat-exchanger 200.

Thereby, the ventilation system according to the present invention hasan advantageous effect that pressure loss may be reduced.

Preferably, the heat-exchanger 100 and 200 of the ventilation systemaccording to the present invention further includes a bypass channel 145and 245 for supplying outside air into the indoor space without outsideair passing the unit heat-exchange element, and a bypass damper (notshown) for selectively shutting off the bypass channel.

In case that the temperature of outside air (OA) and the temperature ofroom air (RA) is almost the same, ventilation is performed through theheat-exchange element 140 and 240 not to consume unnecessaryelectricity. In that case, the bypass channel 145 and 245 connected tothe air-exhaust fan scroll 135 and 235 is opened without room air (RA)exhausted outdoors passing the heat-exchange element 140 and 240. Thebypass damper (not shown) selectively opens the bypass channel.

The bypass channel 145 and 245 and the bypass damper may be provided inthe channel supplied into a room or both channels supplied/exhaustedinto/to a(n) room/outside.

The heat-exchanger 100 and 200 of the ventilation system according tothe present invention may perform air cleansing as well asheat-exchange, because a filter (not shown) is further provided forfiltering foreign substances of air before air is drawn into theheat-exchange element 140 and 240.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A ventilation system comprising: a heat-exchanger having at least twounit heat-exchange elements arranged in parallel for heat exchangebetween supplied outside air and exhausted room air; an air-supply ducthaving one side for making an outdoors be in communication with aninside of the heat-exchanger and the other side for making an indoorspace be room in communication with the inside of the heat-exchanger tosupply outside air into the indoor space; and an air-exhaust duct havingone side for making the indoor space be in communication with the insideof the heat-exchanger and the other side for making the outdoors be incommunication with the inside of the heat-exchanger to exhaust room airoutdoors; wherein an air-supply channel is formed for making one side ofthe air-supply duct be in communication with the other side of theair-supply duct and an air-exhaust channel is formed in a diagonaldirection of the air-supply channel for making one side of theair-exhaust duct be in communication with the other side of theair-exhaust duct within the heat-exchanger.
 2. The ventilation system ofclaim 1, further comprising, an air-supply fan scroll having anair-supply fan for supplying outside air into the indoor space in theair-supply channel and a motor for operating the air-supply fan, and anair-exhaust fan scroll having an air-exhaust fan for exhausting room airoutdoors in the air-exhaust channel and a motor for operating theair-exhaust fan.
 3. The ventilation system of claim 2, wherein theair-supply fan scroll and the air-exhaust fan scroll are provided in thesame portion of the heat-exchanger with respect to the heat-exchangeelement.
 4. The ventilation system of claim 3, wherein the air-supplychannel and the air-exhaust channel are in right/left andupward/downward symmetry.
 5. The ventilation system of claim 4, furthercomprising a guide for partitioning off the air supply channel from theair-exhaust channel.
 6. The ventilation system of claim 5, wherein theheat-exchanger further comprises, a bypass channel for supplying outsideair into the indoor space without outside air passing the unitheat-exchange element, and a bypass damper for selectively shutting offthe bypass channel.
 7. The ventilation system of claim 2, wherein theair-supply fan and the air-exhaust fan are double suction fans,respectively.
 8. The ventilation system of claim 1, wherein the unitheat-exchange element is a total-heat-exchange element.
 9. Theventilation system of claim 8, wherein the unit heat-exchange element isa hexagonal parallel type heat-exchange element.
 10. The ventilationsystem of claim 8, wherein the air passing through the unitheat-exchange element is drawn from an air drawing surface of the unitheat-exchange element in a diagonal direction with respect to a centerof the unit heat-exchange element and discharged from an air dischargingsurface of the unit heat-exchanging surface in a diagonal direction withrespect to a center of the unit heat-exchange element.
 11. Theventilation system of claim 10, further comprising a channel guidecasing formed on an air drawing surface and an air discharging surfaceof the unit heat-exchange element to drawn/discharge air in a diagonaldirection with respect to the center of the unit heat-exchange element.12. The ventilation system of claim 10, wherein the air-supply channeland the air-exhaust channel are partitioned by a guide within theheat-exchanger, the air-supply channel and the air-exhaust channel arein a right/left and upward/downward symmetry within the heat-exchanger.